Spectroscopic Investigation of the Electronic A¹ A′′−χ¹ A′ Transition of HSiNC

The first spectroscopic investigation of the A¹A′′−χ¹A′ transition of HSiNC has been reported. The 0/0° band of the A¹A′′−χ¹A′ transition has been rotational resolved using laser-induced fluorescence spectroscopy, and ground- and excited-state rotational and centrifugal distortion constants were evaluated. Ten additional vibrational bands belonging to HSiNC have also been observed in the laser-induced fluorescence spectrum and have been assigned based on predicted anharmonic vibrational frequencies. Because of the large change in geometry upon excitation, a number of axis-rotation peaks have been observed in the 0/0° band, and the axis-rotation angle (θT) has been estimated to be 1.0 ± 0.2°. Dispersed fluorescence spectroscopy has also been carried out, and a number of overtones of the ν3 fundamental (Si−H wagging mode) have been observed in the ground state, and its anharmonic parameter (xe) was evaluated.